/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.sql.parser.hive.ddl;

import org.apache.flink.sql.parser.ddl.SqlAlterTableProperties;

import org.apache.calcite.sql.SqlIdentifier;
import org.apache.calcite.sql.SqlNodeList;
import org.apache.calcite.sql.SqlWriter;
import org.apache.calcite.sql.parser.SqlParserPos;

/**
 * Abstract class for ALTER DDL of a Hive table.
 * Any ALTER TABLE operations that need to be encoded as table properties should extend this class.
 */
public abstract class SqlAlterHiveTable extends SqlAlterTableProperties {

	public static final String ALTER_TABLE_OP = "alter.table.op";
	public static final String ALTER_COL_CASCADE = "alter.column.cascade";

	public SqlAlterHiveTable(AlterTableOp op, SqlParserPos pos, SqlIdentifier tableName,
			SqlNodeList partSpec, SqlNodeList propertyList) {
		super(pos, tableName, partSpec, propertyList);
		propertyList.add(HiveDDLUtils.toTableOption(ALTER_TABLE_OP, op.name(), pos));
	}

	@Override
	public void unparse(SqlWriter writer, int leftPrec, int rightPrec) {
		writer.keyword("ALTER TABLE");
		tableIdentifier.unparse(writer, leftPrec, rightPrec);
		SqlNodeList partitionSpec = getPartitionSpec();
		if (partitionSpec != null && partitionSpec.size() > 0) {
			writer.keyword("PARTITION");
			partitionSpec.unparse(writer, getOperator().getLeftPrec(), getOperator().getRightPrec());
		}
	}

	/**
	 * Type of ALTER TABLE operation.
	 */
	public enum AlterTableOp {
		CHANGE_TBL_PROPS,
		CHANGE_SERDE_PROPS,
		CHANGE_FILE_FORMAT,
		CHANGE_LOCATION,
		ALTER_COLUMNS
	}
}
